Experimental and numerical investigation of flexible bulging process of aluminum AA1050-H14 sheet metal with soft tools

The purpose of this manuscript is to carry out an experimental and numerical investigation of bulging process of aluminum AA1050-H14 sheet metal in free expansion when using a flexible punch. Three types of rubber with different hardness are used as flexible punch. First, a mechanical characterization and identification of aluminum sheet metal and polyurethane rubber parameters is achieved for validation purpose. Then, an experimental study of flexible bulging process is performed to analyze the effect of rubber type and hardness on forming capability. The obtained results show that the polyurethane with hardness of 70 Shore A is considered as the most suitable punch for the bulging operation when comparing with silicone and natural rubber. Finally, a comparison between bulging with flexible and rigid punches is conducted using the finite element code ABAQUS/Explicit. The developed simulations predict efficiently the realistic thickness distribution along the bulged part.